Abstract

We experimentally investigate the temporal evolution of the power of an
external cavity semiconductor laser in the low-frequency fluctuation regime
with subnanosecond resolution. We show, for the first time to our knowledge, that generally the laser power drops to a value significantly different from
the solitary laser power. We demonstrate the analogy between the recovery
of the laser intensity and the turn-on transient of a semiconductor laser.

Figures (4)

Sampling scope trace of a power dropout
with the laser biased below the solitary laser threshold. After the power
dropout, the laser recovers with pulses separated by the external cavity round-trip
time.

Sampling scope trace of a power dropout
with the laser biased above the solitary laser threshold. Horizontal line, solitary laser power. After the power dropout, the laser recovers with damped
relaxation oscillations, which are reactivated at every round-trip time.

Log of the recovery time versus log of
the pumping parameter. Squares, points taken below the solitary laser threshold, in this case r=i/if-1, where if is the threshold current of the laser with feedback. Triangles, points taken above solitary laser threshold. In this case r=i/isol-1, where isol is the threshold current for the solitary laser.